It all started when a few chunks of concrete broke away from the upper deck of Wrigley Field, the aging home of the Chicago Cubs. Or maybe it began earlier, when the Chicago Tribune published the latest in a string of articles suggesting corruption and cronyism at City Hall. Before long, patented Chicago punches were flying.

Mayor Richard M. Daley (D) ducked a question in July about fat city contracts and instead bashed the Tribune, accusing the newspaper of covering up for the Cubs, who just happen to be owned by the Tribune's parent company. The paper's editorial page accused Daley of trying to change the subject. Daley seemed to relish the chance to declare that the Tribune had a "double standard."

Then the newspaper, saying it was acting on a tip, demanded records about safety at City Hall.

The city, saying it was acting on a tip of its own, halted a construction project at a Tribune Co. television station, WGN.

And on it goes, pitting Chicago's virtually unchallenged five-term mayor against the city's most influential newspaper, with the variously deified and despised Cubs folded into the mix. The stakes appear modest, but the summer spat has produced a delectable show of pique and counter-pique.

"It obviously has very little to do with Wrigley Field," said Michael Miner, media critic for the Chicago Reader, an alternative newspaper. "It's interesting that Daley feels so comfortable . . . mocking the Tribune, which nobody does."

The squabble shows Daley's confidence in his 16th year in office, reelected last time with 79 percent of the vote. At 62, with no obvious opponent on the horizon and no ambitions for higher office, Daley runs Chicago just as much as his imperious father, Richard J. Daley, who died in office in 1976 after 21 years on the job, ever did.

Daley commands the loyalty of a solid majority of the city's aldermen -- he appointed many of them -- and the most important agency heads owe their jobs to him. Unlike his father, who earned open hostility from the African American community, the current Mayor Daley overcame early doubts to win a strong majority of the black vote -- 61 percent in 2003.

"He has a remarkable degree of control. He has alliances across race and ethnicity. He is admired and assumed to be permanent by most people," DePaul University political scientist Larry Bennett said. He added that Daley is also "intrinsically thin-skinned."

Where Daley has been hit hardest is on the city's contracting practices, with journalists and critics excavating the political connections of the winning bidders and what might kindly be called bureaucratic sleight of hand.

The Tribune has led the way with repeated investigations and front-page exposes. Members of the politically connected Duff family are to stand federal trial next month, for instance. A Tribune investigation reported that a company run by Duff men won $100 million in contracts designated for women and minorities by pretending their mother was the firm's owner and by using a front company ostensibly run by an African American.

It was at a July 21 news conference, when the mayor was asked about a Tribune report about alleged irregularities in a multimillion-dollar garbage truck contract, that he fired back about Wrigley Field. Daley accused the Tribune of covering up for its parent, Tribune Co., which owns the newspaper and the Cubs.

"That incident should have been fully disclosed. You hide the news," Daley said, referring to a piece of concrete that broke away from the upper deck the previous month. If a piece of concrete fell from City Hall or Soldier Field, home of the Chicago Bears, he said, "you would have an editorial, right?"

Daley-watchers said the mayor seemed delighted to have discovered a stick with which to smack the Tribune. The paper had recently pointed out in a front-page story that Millennium Park, Daley's grandly ambitious showcase on Lake Michigan, was about to open four years late and more than three times as expensive as first thought.

Columnist John Kass had been clobbering Daley regularly: "People believe him? What's next, that he killed seven giants with one blow?" And the Tribune's architecture critic, Blair Kamin, had panned the overhaul of Soldier Field, a favorite of the mayor's, by saying it looked as though the Starship Enterprise had crash-landed atop the Lincoln Memorial.

"I think he does enjoy it, maybe because he knows he could shut down some of their operations," said Richard Roth, associate dean at Northwestern University's Medill School of Journalism. He also said Tribune Co. left itself open to criticism by owning the team and the newspaper, which he said "gives the Cubs more attention and better play than it gives the White Sox."

When Daley, who is a White Sox fan to boot, blasted the Tribune and threatened to close Wrigley Field, the Tribune's editors protested that the newsroom was not influenced by the corporate parent's ownership of the baseball team.

"He probably sees this as some kind of conspiracy at Tribune Tower. It's not," James O'Shea, the Tribune's managing editor, said in an interview. "It's one of the penalties you pay when you own a baseball team in your newspaper organization. We cover the Cubs very aggressively. We try not to be overly critical simply because we own them. We don't ignore things because we own them."

The flap worsened when Cubs executives admitted that they had made more than $1 million in repairs to 90-year-old Wrigley Field without city permits. Then, on Aug. 5, the Tribune made a Freedom of Information Act request to the city's building department about the facade of City Hall.

Daley smelled a rat.

"Is this the Chicago Cubs or the Chicago Tribune?" he asked. "Both."

Editors, who recognized the inevitable backlash that would greet the request, said they felt a responsibility to pursue a tip about alleged maintenance problems. Seven days later, as City Hall released those records, a building inspector discovered that Tribune-owned WGN was constructing a satellite tower without a building permit.

"I sent somebody out because that's what I do when I get tips about construction that isn't permitted," Stan Kaderbek, the city building commissioner, said in an interview. "I have a job to do, and I don't care if it's the Tribune. I don't care if it's City Hall."

Don Rose, a political consultant and longtime critic of the Daleys, sees the affair differently.

"Sending the building inspectors is old-fashioned political payback," Rose said. "In the old days of Chicago politics, if you didn't get along with your alderman, they'd send an inspector along to look at your basement. The code is such that there isn't a basement in town that doesn't have some kind of violation."

As the feud continued, the Tribune editorial page answered Daley with a piece headlined "Here's your editorial, Mayor." It criticized the Cubs for failing to come clean but said the bigger problem was Daley being "driven to distraction" by news organizations that "have the temerity to question him in public."

No word yet, however, on whom the Tribune would endorse if Daley seeks a sixth term. The paper's editorial board has backed him every time he has run for mayor.

Special correspondent Kari Lydersen contributed to this report.

Falling concrete at Wrigley Field, home of the Tribune Co.-owned Chicago Cubs, gave the five-term mayor ammunition against the city's largest newspaper. Mayor Richard M. Daley has bristled at Tribune reports about City Hall.